Apparatus for removing burr from the ends of pinion teeth

ABSTRACT

Apparatus for removing burrs from the ends of pinion teeth comprising an aperture having a cross-section corresponding to the intended cross-section of a pinion to be deburred and and rams for reciprocating the pinion relative to the aperture. The aperture is defined by a plurality of fingers corresponding to the number of pinion teeth arranged radially of the axis of the aperture and mounted on a disc. Each finger has a peg extending into a slot which extends lengthwise in a direction inclined at an angle to the normal of a radius of the disc passing through the aperture axis so that angular movement of the disc causes radial movement of the fingers into or out of their aperture defining positions.

United States Patent [191 Flint [451 Apr. 9, 1974 APPARATUS FOR REMOVING BURR FROM THE ENDS OF PINION TEETH [75] Inventor: Ronald Derek Flint, Solihull,

England [73] Assignee: Joseph Lucas (Industries) Limited,

Birmingham, England [22] Filed: Apr. 28, 1972 [21] Appl. No.: 248,646

[30] Foreign Application Priority Data May I, 1971 Great Britain 12592/71 [52] US. Cl. 90/1-4, 90/24 E [51] Int. Cl 1323f 19/10 [58] Field of Search 90/l.4, 1.6, l, 24 A, 24 E [56] References Cited UNITED STATES PATENTS 2,343,407 7/1944 Galloway 90/l.4

Primary Examiner-Gil Weidenfeld- Attorney, Agent, or Firm-Holman & Stern [5 7] ABSTRACT Apparatus for removing burrs from the ends of pinion teeth comprising an aperture having a cross-section corresponding to the intended cross-section of a pinion to be deburred and and rams for reciprocating the pinion relative to the aperture. The aperture is defined by a plurality of fingers corresponding to the number of pinion teeth arranged radially of the axis of the aperture and mounted on a disc. Each finger has a peg extending into a slot which extends lengthwise in a direction inclined at an angle to the normal of a radius of the disc passing through the aperture axis so that angular movement of the disc causes radial movement of the fingers into or out of their aperture defining positions.

8 Claims, 4 Drawing Figures PATENTEUAPR 91974 3 802314 SHEET 1 OF 2 v FIGQI APPARATUS FOR REMOVING BURR FROM THE ENDS OF PINION TEETH This invention relates to apparatus for removing burrs from the ends of pinion teeth and more particularly but not exclusively to apparatus for removing burrs from the ends of the teeth of a pinion of a starter motor assembly used in road vehicles.

It is an object of the present invention to provide such apparatus in a convenient form.

In accordance with the present invention there is provided apparatus for removing burrs from the ends of pinion teeth, said apparatus comprising a pinion receiving assembly including an aperture for receiving the pinion and a plurality of fingers equal in number to the number of teeth on the pinion, said fingers being, in use, movable radially inwardly into engagement with parts of the pinion teeth intermediate the ends thereof and the inner ends of the fingers being shaped so that when they are moved into engagement with said parts of the pinion teeth they form an annulus having an internal configuration which is complementary to the external configuration of the pinion teeth, there being further provided means for effecting relative axial movement between said pinion and said assembly in both directions whereby said fingers will, in use, and on such relative axial movement, remove the burrs from the ends of the pinion teeth.

Preferably, each finger is provided with an axially extending peg which is located in a slot formed in a disc, the latter being centred on the axis of said aperture and being angularly movable relative to the fingers, each slot extending lengthwise in a direction inclined at an angle, preferably not greater than 7%.", to the nonnal of a radius of the disc passing through one end of the slot such that angular movement of the disc will effect radial movement of said fingers.

Conveniently, angular movement of said disc is effected by fluid pressure actuated means.

Desirably, said pinion is axially movable relative to said assembly by a pair of fluid-pressure actuated rams acting in opposed axial directions.

The invention will now be more particularly described with reference to the accompanying drawings wherein:

FIG. 1 is an end view of one embodiment ofapparatus according to the present invention,

FIG. 2 is a sectional view taken along the line 2-2 of FIG. 1,

FIG. 3 is a view of part of the apparatus shown in FIG. 2, and

FIG. 4 illustrates a pneumatic circuit used in conjunction with the apparatus shown in FIGS. 1 to 3.

Referring more particularly to FIGS. 1 and 2 of the accompanying drawings, there is shown therein apparatus for removing burrs from the ends of the teeth of a pinion of a starter motor assembly used in road vehicles. Such pinions are manufactured by extrusion followed by a machining process which leaves burrs on the ends of the pinion teeth. Hitherto, these burrs have been removed by pressing the pinion through a solid die. However, this process has not been very successful since the dimensions of each pinion varies slightly and thus the die either does not remove all the burrs or the pinion sticks in the die. Furthermore, one end (namely, the leading edge when the pinion is in use) of the pinion teeth is normally chamfered and as a result the aforesaid die does not remove burrs from this end.

The apparatus shown in FIGS. 1 and 2 comprises a pinion receiving assembly which has an aperture 1 1 arranged, in use, to receive a pinion 12. The pinion receiving assembly 10 comprises a drum l3 and a disc 14 which is mounted on one axial end of the drum 13 for angular movement relative thereto. The aperture 11 is formed co-axially in the drum 13 and the disc 14. A plurality of fingers 15 (as shown ten such fingers are provided) are mounted in grooves 16 formed in said one axial end of the drum 13. The fingers 15 are equiangularly spaced around the aperture 1 l and these fingers 15 are radially inwardly movable so as to engage parts of the pinion teeth intermediate the ends thereof in use. The inner ends of the fingers are shaped so that when they are moved into engagement with said parts of the pinion teeth they form an annulus (as shown more particularly in FIG. 1) having an internal configuration which is complementary to the external configuration of the pinion teeth. Each finger 15 is provided adjacent its outer end with an axially extending peg 17 which is located in a slot 18 formed in the disc 14. Each slot 18 extends lengthwise in a direction inclined at a small angle (desirably this angle does not exceed 7%) to the normal of a radius of the disc 14 passing through one end of the slot 18.

Thus, angular movement of the disc 14 relative to the drum 13 in one direction will cause the fingers 15 to move radially inwardly or radially outwardly dependent upon the direction of angular movement of the disc 14. Such angular movement of the disc 14 may be effected by fluid pressure actuated means in the form of a pneumatic ram 19. To this end the free end of a piston rod 20 of the ram 19 is connected to the disc 14 adjacent the circumference thereof through the intermediary of a link 21. A link 21 is pivotally connected at its one end to the free end of the piston rod 20 and is rigidly connected at its other end to the disc 14.

Means are also provided for effecting relative axial movement between the pinion 12 and the pinion receiving assembly 10 in both directions whereby the fingers 15 will, in use, and on such relative axial movement, remove the burrs from the ends of the pinion teeth. Preferably, such means are in the form of a pair of hydraulic rams 22 and 23 which act in opposed axial directions. The hydraulic ram 22 is mounted such that on actuation thereof the free end of the piston rod 24 v of the ram 22 engages that axial end of the pinion 12 which is adjacent the disc 14 so as to move one end of the pinion teeth axially past one cutting edge 15a of the fingers 15. However, actuation of the hydraulic ram 22 does not move the pinion 12 completely out of engagement with the fingers 15. The hydraulic ram 23 is mounted on an assembly 25 which is connected to the other axial end of the drum l3 and the piston rod 26 of the ram 23 is biased to an inoperative position by a compression spring 27. The free axial end of the piston rod 26 of the ram 23 has mounted therein a spring loaded plunger 28 which is biased by a compression spring 29 in a direction towards the hydraulic ram 22. The hydraulic ram 23 is arranged to move in a direction such that the plunger 28 engages the other axial end of the pinion 11 so as to move the other end of the pinion teeth past another cutting edge 15b of the fingers 15 opposite said one cutting edge 15a. However, upon initial axial movement of the piston rod 26 of the hydraulie ram 23 the plunger 28 engages the pinion 12 and the spring 29 compresses. The reason for providing the spring loaded plunger 28 will become apparent hereinafter.

Referring now more particularly to FIG. 3 of the drawings, the free end of the piston rod 24 of the hydraulic ram 22 is shown therein and a sleeve 30 is mounted on the piston rod 24 adjacent the free axial end thereof. The sleeve 30 is provided at each of its axial ends with a cam surface 31 and 32 which are arranged to engage operating members 33 and 34, of a pair of changeover valves 35 and 36 respectively. The changeover valves 35 and 36 are mounted in fixed relationship to the assembly and these changeover valves form part of a pneumatic control circuit shown more particularly in FIG. 4. The operating members 33 and 34 are spring biased towards the piston rod 24 and FIG. 3 illustrates the sleeve 30 in a position in which the piston rod 24 is commencing to retract, the cam surface 32 being in a position in which it is about to disengage from the operating member 34.

Referring now more particularly to FIG. 4 of the accompanying drawings, there is shown therein a pneumatic control circuit for operating the hydraulic ram 23 in accordance with the position of the hydraulic ram 22. Hydraulic fluid is supplied to the ram 23 from a pneumatic actuated booster 37. The booster 37 is actuated by air supplied through a supply line 38 from a pump 39 via a control valve 40. As illustrated in FIG. 4, the operating member 33 of the change-over valve 35 is engaged by the cam surface 31 whilst the changeover valve 35 is in its spring-biased position. At this stage, the control valve 40 is in a position in which line 38 is vented to atmosphere having been shifted by air supplied from pump 39 via valve 35 and line 42. Thus, retraction of piston rod 26 of hydraulic ram 23 is permitted during extension of piston rod 24 of hydraulic ram 22. When piston rod 24 has extended to a position in which cam surface 32 has contacted operating member 34 of change-over valve 36, change-over valve 35 having previously adopted its spring-biased position after release of operating member 33 by cam surface 31, the control valve is moved to the right in FIG. 4 by air supplied from pump 39 via valve 36 and line 41 so as to connect booster 37 to the pump 39 via line 38 and thus to cause extension of piston rod '24 of hydraulic ram 23. In this way, in use, reciprocation of the pinion 12 relative to the fingers is effected. It is to be appreciated that hydraulic fluid at relatively low pressure is applied to hydraulic ram 22 so that extension of piston rod 26 of hydraulic ram 23 is possible due to the higher pressure supplied to the latter.

In operation and starting with the fingers 15 in a retracted position and the hydraulic ram 22 also in a retracted position, a pinion 12 is inserted into the aperture 11 in the pinion receiving assembly 10. When the operator of the apparatus closes an apparatus guard (not shown) this causes actuation of the pneumatic ram 19 to move the disc 14 angularly relative to the drum 13 which in turn causes the fingers 15 to move radially inwardly into engagement with the pinion teeth. Extension of the piston rod 24 is then initiated in a direction towards the pinion 22 by supplying low pressure hydraulic fluid for the ram 22. The pinion 12 is thus pressed against the spring loaded plunger 28 to compress the Spring 29 and the burr on the one end of the pinion teeth is removed by cutting edge 15a of the fingers 15. During this movement of the piston rod 24 the supply line 38 has been vented to atmosphere and reciprocation of the pinion 12 is effected by operation of the control circuit as described hereinabove. During extension of the piston rod 26 the burr on the other end of the pinion teeth is removed by cutting edge 15b of the fingers 15. Upon completion of the deburring operation, when the aforesaid apparatus guard is re-opened air is supplied to the ram 19 to cause the disc '14 to move angularly in the opposite direction and this effects movement of the fingers 15 radially outwardly. The pinion 12 is removed from the pinion receiving assembly l0 and a new pinion is inserted whereupon the cycle is repeated.

The provision of the spring loaded plunger 28 ensures that a pinion 12 inserted in the pinion receiving assembly 10 always abuts the free axial end of this plunger 28 and this maintains correct positioning of the pinion 12 in the pinion receiving assembly 10,

I claim:

1. Apparatus for removing burrs from the ends of teeth on a pinion, said apparatus comprising an assembly for receiving'thepinion, and means for efi'ecting relative axial movement between the pinion and said assembly in both directions, said assembly including means defining an aperture for receiving the pinion, a plurality of fingers equally numbered to the number of pinion teeth, and means for effecting radial movement of all of said fingers between a retracted position for receiving the pinion and a radially inward position at which the fingers contact the pinion teeth thereby permitting pinions of slightly varying dimensions to be accommodated, inner ends of said fingers having opposed cutting edges thereon, said inner ends being shaped so that, when said fingers are in said radially inward position in contact with the pinion teeth, there is defined an annulus having an internal configuration which is complementary to the external configuration of the pinion teeth whereby said opposed cutting edges will, on relative axial movement between the pinion and said assembly, remove the burrs from the ends of the pinion teeth.

2. The apparatus according to claim 1, wherein each finger is provided with an axially extending peg which is located in a slot formed in a die, said disc being centred on the axis of said aperture and being angularly movable relative to said fingers, each slot extending lengthwise in a direction inclined at an angle to the normal of a radius of said disc passing through one of said slot such that angular movement of said disc will effect radial movement of said fingers.

3. The apparatus according to claim 2, wherein said angle of inclination is not greater than 7%.

4. The apparatus according to claim 2, wherein fluid pressure actuating means is providing for effecting angular movement of said disc.

5. The apparatus according to claim 1, wherein said means for effecting relative axial movement between said pinion and said assembly comprises a pair of fluidpressure actuated rams acting in opposed axial directions.

6. The apparatus according to claim 5, wherein said rams have longitudinal axis which are aligned with said aperature and are adapted to operate on the pinion to move the latter relative to said assembly.

7. The apparatus according to claim 5, wherein a pair of cams are associated with one of said rams to be mov- 6 able therewith, and a pair of change-over valves in a 8. The apparatus according to claim 6, wherein one control circuit for the other ram are selectively engageof said rams has a piston rod to which is attached a able with the respective cams for controlling the movement of the said other ram so as to cause, in use, reciprocation of the pinion. 5

spring-loaded plunger for engaging the pinion, in use. 

1. Apparatus for removing burrs from the ends of teeth on a pinion, said apparatus comprising an assembly for receiving the pinion, and means for effecting relative axial movement between the pinion and said assembly in both directions, said assembly including means defining an aperture for receiving the pinion, a plurality of fingers equally numbered to the number of pinion teeth, and means for effecting radial movement of all of said fingers between a retracted position for receiving the pinion and a radially inward position at which the fingers contact the pinion teeth thereby permitting pinions of slightly varying dimensions to be accommodated, inner ends of said fingers having opposed cutting edges thereon, said inner ends being shaped so that, when said fingers are in said radially inward position in contact with the pinion teeth, there is defined an annulus having an internal configuration which is complementary to the external configuration of the pinion teeth whereby said opposed cutting edges will, on relative axial movement between the pinion and said assembly, remove the burrs from the ends of the pinion teeth.
 2. The apparatus according to claim 1, wherein each finger is provided with an axially extending peg which is located in a slot formed in a dic, said disc being centred on the axis of said aperture and being angularly movable relative to said fingers, each slot extending lengthwise in a direction inclined at an angle to the normal of a radius of said disc passing through one end of said slot such that angular movement of said disc will effect radial movement of said fingers.
 3. The apparatus according to claim 2, wherein said angle of inclination is not greater than 7 1/2 *.
 4. The apparatus according to claim 2, wherein fluid pressure actuating means is providing for effecting angular movement of said disc.
 5. The apparatus according to claim 1, wherein said means for effecting relative axial movement between said pinion and said assembly comprises a pair of fluid-pressure actuated rams acting in opposed axial directions.
 6. The apparatus according to claim 5, wherein said rams have longitudinal axis which are aligned with said aperature and are adapted to operate on the pinion to move the latter relative to said assembly.
 7. The apparatus according to claim 5, wherein a pair of cams are associated with one of said rams to be movable therewith, and a pair of change-over valves in a control circuit for the other ram are selectively engageable with the respective cams for controlling the movement of the said other ram so as to cause, in use, reciprocation of the pinion.
 8. The apparatus according to claim 6, wherein one of said rams has a piston rod to which is attached a spring-loaded plunger for engaging the pinion, in use. 